The present disclosure relates to opening and closing devices for openable bodies and image scanner units and particularly relates to a technique for assisting the opening and closing operation of an openable body.
As an example of an opening and closing device for assisting the opening and closing operation of an openable body, there is known an opening and closing device A including: a mounting member provided on a unit body of a unit; and a support member provided on an opening/closing member of the unit, wherein the support member is pivotally supported by a hinge pin from the mounting member, so that the opening/closing member is supported from the unit body so as to be openable and closable with respect to the unit body. Furthermore, this opening and closing device A is designed so that when a cam follower provided on the support member is pressed against a cam provided on the mounting member, a reaction force on the support member causes the opening/closing member to be held open against a moment in a direction of closing of the opening/closing member due to its own weight. Moreover, when the opening/closing member is opened to its maximum opening angle, the support member abuts on a stopper to restrict the opening angle of the opening/closing member.
As another example of the opening and closing device, there is known an opening and closing device B for supporting a document feeder from an image scanner unit by a hinge so that the document feeder can be opened and closed with respect to the image scanner unit. This hinge includes a fixed member provided on the image scanner unit, a movable member provided on the document feeder, and a pin supporting the movable member pivotally from the fixed member. Furthermore, the hinge is designed so that when the document feeder is opened largely, the movable member abuts on a stopper of the fixed member to restrict the opening angle of the document feeder.